Pro Desk Backpack

ABSTRACT

An advanced backpack that converts into a sturdy, potable, student desk via adjustable legs housed on all four sides at the bottom of the Backpack and a HARD desk top surface that can be extended out to create a larger desk top. The backpack will have a 360 degree zipper on compartment #4 of the backpack so the backpack can be completely detached from the base of the Potable Desk backpack if desired. The Backpack will be designed comparable to most Backpack but will separate itself from ALL Backpacks as it can turn into a Potable Desk. Prior designs of backpack stopped at being a housing unit for books and supplies but mine has advanced the backpack by adding adjustable legs on all 4 sides of the bottom of the backpack to enable the backpack to be used as a Potable Desk along with being a housing unit for books and supplies. The Backpack&#39;s Potable Desk will be designed so it can be used by a customer standing up or sitting down. The Backpack&#39;s Potable Desk surface will be adjustable so it can be extended and/or retracted to create a larger work desk. The backpack will also have a water proof UBS charging port to house two USB charging station and a charging port, a cup holder, an anti-theft device, a pencil holder on the desk and some backpacks will have wheels and a walking handle for travel conveyance.

BACKGROUND OF THE INVENTION

Travelers and commuters have long used backpacks aka book bags to carry a variety of items. Students use backpacks to carry their school books and supplies while hikers utilize backpacks for carrying and housing their hiking supplies. However backpacks have been limited in their usage to simply being a carrying and housing unit. All this will change as the Advanced Backpack can transform into a workable desk where students can now do their school assignments on their front steps, back porch, at a park sitting on a park bench, on the subway or at a coffee shop. Hikers can use their Advanced Backpack to set up a dining table on a mountain top. Users' can now charge their phones and other electronic devices from the Advanced Backpack that has TWO USB charging port and a cup holder all which is NOT readily available on conventional backpacks as the use of combination backpacks and a hard surface work table/desk is NOT known in the other patents more specifically, combination backpack and student desk top.

The use of combination backpack and work table is known in the other patens more specifically, combination backpack and work table heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configuration, notwithstanding the myriad of designs encompassed by the crowed prior art which have been developed for the fulfillment of countless objectives and requirements.

Known prior arts includes U.S. Pat. Nos. 7,593,222 B2; 4,856,627; 6,068,355; 4,790,416; 5,242,218; 4,244,632; U.S. Pat. No. Des. 394,954; U.S. Pat. No. 6,811,006 B1; U.S. Pat. No. 2010/0124013 A1; U.S. Pat. No. 2002/0057552 A1; and U.S. Pat. No. 007593222 B2.

While these devices fulfill their respective, particular objective and requirements, the aforementioned patents do not disclosed a new backpack with a student desktop with adjustable legs, extended hard surface desk top, two PORTABLE USB charging port, anti-theft device, a pencil holder on top of student desk and a cup holder. Prior art stopped at solely being a housing unit for books and supplies while mine advanced it by becoming a combination backpack and work table with a desktop with adjustable legs, extended desk top, PORTABLE USB charging port, anti-theft unit, a pencil holder and a cup holder.

SUMMARY OF THE INVENTION

The Portable Desk Backpack will serve as a regular Backpack while also having the ability to transform into a sturdy student desk when all four legs on all four sides of The Portable Desk Backpack are used. The legs on the Backpack will be adjustable to reach different heights to suite each customer comfortably. The base of each leg will have a secure circular base to ensure sturdiness and stability on any and all surface. The Portable Desk Backpack will also have a retractable desk table that can slide out on each side to extend the size of the desk to suite customers comfortably. The Portable Desk Backpack will have a comfortable neck and waist harness so The Portable Desk Backpack can be used by a customer standing up and the desk will remain stable and sturdy. The Portable Desk Backpack will have a two PORTABLE USB charging station so customers can charge their cell phones and other electrical dives as well as a cup holder, anti theft device and the desk top will have a pencil holder. The Portable Desk will also have a shoulder and waist harness so the portable desk can be used while standing.

The dimensions of The Portable Desk Backpack as it relates to its length and width will be 17 in. and 19 in. respectively and can be extended out via a retractable right and left sidewalls to 23 in. and 25 in in length and width. The bottoms of the backpack's arm/shoulder straps are detachable whereas the straps won't interfere with the usage of the desktop.

The Portable Desk Backpack has 5 compartments and a desk top base;

Compartment #1 is the smallest size compartment made of material used to house pens, pencils, small note pads, make-up and a calculator. Compartment #2 is a medium size compartment made of waterproof material and is used to house the charging station and the charging port. It can house small items such as cell phones and keys. Compartment #3 is a lager compartment of the backpack which can be used to house notebook pads and folders.

Compartment #4 is a larger and wider compartment than compartment #3 which can be used to house a number of large books. Compartment #5 has a 360 degree zipper so it can completely detach itself from the Base. Once detached from the base, Compartment #5 allows the customer to separate the backpack completely from the desk/table for easier comfort when working on the work desk. But the customer doesn't have to completely detach the Compartment #4 from the base to utilize the desk top.

The desktop base—The base is the compartment that rest on the customer's back and will have the arm/shoulder straps and where the adjustable table legs are housed. This compartment will be made of material on the outside but made of standards hard “Desk top” material on the inside. This compartment will house the retractable table top for the expansion of the Potable Desk work station.

BRIEF DESCRIPTION OF THE DRAWINGS

Various examples of objects, features and intendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawing, in which like reference, characters, designate the same or similar parts throughout the several views. For the purpose of illustrating the invention, there are shown in the drawing forms which are presently preferred; it being understood, however that this invention is NOT limited to the precise arrangements and instrumentalities shown.

FIG. 1 shows a front view of a backpack showing my design;

FIG. 2 shows an elevational view of a backpack when used as a desk top when the extendable legs are extended down thereof;

FIG. 3 shows a front and side view of a backpack and the various compartments of a backpack thereof;

FIG. 4 shows the bottom of a backpack where the extendable legs are housed thereof;

FIG. 5 shows the bottom and an elevational view of a backpack. The bottom view of a backpack shows the legs on a backpack and how they can be unlocked and lowered while the elevational view shows the base of a backpack when completed separated from its compartments and becomes a desk thereof;

FIG. 6 shows an elevational view of the side and bottom of a backpack's legs that are housed on all 4 sides of a back pack thereof;

FIG. 7 shows a bottom view of a backpack with one of the leg on a backpack extended down thereof;

FIG. 8 shows a bottom view of a backpack with all 4 legs on a backpack extended down thereof;

FIG. 9 shows a front and side view of a backpack thereof;

FIG. 10 shows a front and side view of a backpack with the base of the backpack being separated from the backpack via a 360 degree zipper thereof;

FIG. 11 shows an elevational view of a back pack with the dimensions of the desktop surface thereof;

FIG. 12 shows an elevational view of a backpack with the dimensions of the desktop surface when expanded to become a larger desk top surface thereof;

FIG. 13 shows a front view of a backpack with the base of a backpack is separated from the backpack and converted into a desk thereof;

FIG. 14 shows a front view of a backpack detached from its base and can be carried via a carrying handle on the top of a backpack thereof;

FIG. 15 shows a side view of a backpack being used while standing via a neck harness strap, a waist harness strap and extendable legs thereof;

FIG. 16 shows a side view of a backpack being used while standing via a waist harness strap and extendable legs thereof;

FIG. 17 shows a side view of a backpack's desktop being used in the standing position via a neck and a waist harness straps thereof;

FIG. 18 shows an elevational view of a backpack's detachable shoulder straps being detached as so the shoulder straps don't interfere with the desktop being fully utilized thereof;

FIG. 19 shows a side view of a backpack with the waist harness strap and the extendable legs of a backpack being utilized thereof;

FIG. 20 shows an elevational view of a backpack's shoulder strap connected to the base of the backpack thereof;

FIG. 21 shows a bottom view of a backpack. The housing compartment on the base of the backpack for the shoulder and waist straps thereof;

FIG. 22 shows an elevational view of a backpack with the backpack's cup holder being extended out and utilized thereof;

FIG. 23 shows a front view of a backpack where the PORTABLE USB charging port is housed thereof;

FIG. 24 shows a front view of a backpack and how the PORTABLE USB charging port is utilized thereof;

FIG. 25 shows a front view of a backpack's carrying handle and wheels thereof;

FIG. 26 shows a side view of a backpack being used as a desk in conjunction with a cup holder thereof;

FIG. 27 shows a bottom view of a backpack and how the FOLDABLE legs are housed in the bottom of a backpack thereof;

FIG. 28 shows the bottom view of a backpack. One of the backpack's foldable leg are folded down thereof;

FIG. 29 shows the bottom view of a backpack. One of the backpack's foldable leg is folded down and extended out thereof;

DETAILED DESCRIPTION

This invention concerns a Backpack/book bag that can be converted into a desk via a telescopic leg so that, in addition to being usable for conventional Backpack/book bag, i.e. for books, notebook pads and supplies it can be used for further purpose for which conventional Backpack/book bags are not usually applicable, thereby rendering my Backpack/book bag much more useful and versatile than a conventional Backpack/book bag.

With respect to the below description then, it is to be realized that the optimum dimensional relationship for the parts of the invention, to include variations in size, materials, shape, form, function, and manner of operation. Assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawing and described in the specifications are intended to be encompassed be the present invention.

Also while the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated.

Generally speaking, the Advanced Backpack FIG. 1-4 comprises a specially designed modified carrying bag system that features an Advanced Backpack. One consisting of legs used to create desk top FIG. 2, member 13, a locking mechanism to keep legs locked at desired height member 14, an oval shaped leg base to ensure sturdiness on all floor surfaces member 15 and a housing unit on the bottom of the base of the backpack for the extendable and retractable legs FIG. 4, member 23.

The Advanced Backpack has a hard surface desk top FIG. 2, member 12 with a pencil holder FIG. 2, member 17. The Advanced Backpack desk top can be retracted out to create a larger desk top FIG. 12. The user would simple extend out the left sidewall FIG. 12, member 26 and right sidewall FIG. 12, member 27.

The Advanced Backpack has a locking and unlock knob to lower the extendable legs FIG. 4, member 23.

The Advanced Backpack has a detachable shoulder strap FIG. 5, member 9 so the shoulder strap does not interfere with the full usage of the desktop, a female clip FIG. 4, member 6 to be used with the waist harness strap FIG. 15, member 34 (bottom insert) when using the Potable Backpack in the standing position FIG. 15 and latches FIG. 2, member 16 on the desktop used to connect neck harness FIG. 15, member 31 to the desk top when using the Portable Backpack in the standing position. A waterproof exterior compartment FIG. 1, member 1 used to house the PORTABLE USB charging station and a zipper that can unzip 360 degrees FIG. 2, member 5 so where the backpack can be completely separated from its base FIG. 10, member 5. Each advanced Backpack FIG. 1 could be essentially, BUT NOT LIMITED to being, oval in shape and size copiously to house a wide array of both personal, business and school related items.

Each backpack FIG. 1 will preferably be similar in appearance to a standard backpack and could be produced using preferably constructed of a durable, lightweight and flexible woven or non-woven fabric material such as nylon (e.g., Codura™, rip-stop), cotton, polyester pack-cloth, PVC, reinforced, waterproof textile material such as durable and breathable Gore-Tex. Positioned on the back of the backpack FIG. 1 will preferably be two adjustable shoulder straps member 7 designed for easy transport with adjustable straps member 8 to accommodate each user's individual body type and to offer resistance and comfort.

A backpack handle FIG. 1, member 10, a water bottle housing unit FIG. 1, member 11, and three zippers FIG. 1, member 2, 3 and 4 for access into compartments number 1, 3 and 4 respectively.

Positioned on the backpack FIG. 3 will be 5 compartments. Compartment #1 FIG. 3, member 2 is the smallest size compartment used to house pens, pencils, small note pads, make-up and calculator.

Compartment #2 FIG. 3, member 1 is a medium size compartment made of waterproof material and is used to house the PORTABLE USB port to charge electrical devices like cell phones. It can house small items such as cell phones and keys.

Compartment #3 FIG. 3, member 43 is a lager compartment of the bag which can be used to house notebook pads and folders.

Compartment #4 FIG. 3, member 44 is a larger and wider compartment than compartment #3 which can be used to house a number of large books.

Compartment #5 FIG. 3, member 45 has a 360 degree zipper member 5 so it can completely detach it's self from the Base FIG. 3, member 60. Once detached from the base, Compartment #5 allows the customer to separate the backpack completely from the desk/table for easier comfort when working on the work desk. But the customer doesn't have to completely detach the Compartment #4 from the base to utilize the desk top.

Generally speaking, the Advanced Backpack FIG. 4-9 has specially designed legs housed on the bottom of the Portable Backpack FIG. 4, which NO other backpack has.

The Advanced Backpack will have two different types of housing units for the legs. FIGS. 7-8 are retractable legs on the bottom of the Backpack's base while FIG. 27-29 are foldable legs. The customer can choose from either of the two styles that suits them.

The Advanced Backpack FIG. 27-29 extendable legs will be foldable and they will lay flat on all 4 sides of the bottom of base FIG. 27 of The Portable Backpack while FIG. 9-10 retractable legs will be housed on the bottom of the backpack's base on all 4 sides and extended down via a twist lock FIG. 10 (insert), member 21.

The Advanced Backpack foldable legs FIG. 27-29 will be housed on the bottom of the backpack's base FIG. 27. The Portable Backpack legs can be utilized where as the customer only needs to pull the legs down via a folding latch FIG. 28, member 17 and then adjust the legs to their desired height FIG. 29 member 13, 14 & 15.

The Advanced Backpack FIG. 27-29 can be transformed to a work desk FIG. 2 when compartment #3 FIG. 28 is unzipped and all four extendable legs are lowered.

FIG. 4-9 retractable legs will be housed on the bottom of the backpack's base on all 4 sides and extended down via a twist lock FIG. 5 (insert), member 23.

The Advanced Backpack legs can be unlocked from the housing unit as illustrated in FIG. 5 (insert), member 23. The locking mechanism on each leg can be turned clock wise to lock and counter clock wise to unlock.

The Advanced Backpack legs can be locked, unlocked, extended and retracted via the male grove FIG. 5, member 61 (insert/bottom half) and the female grove FIG. 5, member 62 (insert/bottom half) locking latch. The user would then unlocked the leg and extended it out FIG. 7 member 13, 14, 15 & 23. The user would then repeat these same steps to extend all four legs FIG. 8.

The Advanced Backpack base FIG. 10, member 60, using the 360 zipper FIG. 10, member 5 can be completely detached from compartment #5 FIG. 10, whereas the base can be used as a desktop FIG. 11. One detached the user can use the base as a workstation FIG. 13 to complete school and job related task as well as an outdoor dining table for hikers. Once the base is detached from the backpack, the backpack can still be conveniently carried via the carry handle FIG. 14, member 10 that's on the backpack where as all other backpacks has the “carry handle” on the base of the backpack.

The dimensions of the desktop are 17 in×19 in FIG. 11 however the Advanced Backpack desk top can be retracted out to create a larger desk top surface FIG. 12. The user would simple extend out the left sidewall FIG. 12, member 26 and right sidewall FIG. 12, member 27. The Advanced Backpack can be used by the consumer while standing FIG. 15-19 in 3 different ways;

Generally speaking, the Advanced Backpack FIG. 15 can be used by a person while standing via a combination of using the neck harness strap FIG. 15, member 29, the waist harness strap member 33 with the extendable legs member 13, 14 & 15.

Generally speaking, the Advanced Backpack FIG. 16 can be used by a person while standing via a combination of using the waist harness strap FIG. 16 member 33 with the extendable legs member 13, 14 & 15. The user can easily use the waist harness strap by simply connecting the waist harness strap end FIG. 16 member 34 to the base of the briefcase FIG. 16 member 6 (insert). The user could then tighten the waist harness strap to their desired comfort via the adjustable strap latch FIG. 16 member 32.

The Advanced Backpack can be used by the consumer while standing FIG. 17 by using a combination of the attachable and detachable neck harness FIG. 17, member 29 and the waist harness FIG. 17, member 33. The neck harness' can be used by clipping the end clip of the neck harness FIG. 17 member 31 (top insert), onto the clamp on the desk top's base FIG. 17 member 16 (inset). Once clamped together FIG. 17, the user would then adjust the neck harness strap FIG. 17, member 30, to their desired tightness and comfort. Then the user would take the waist harness' male clip end FIG. 19 member 34 and insert it into the female latch FIG. 19, member 6. To secure the waist strap around the users waist to the base of the desk top FIG. 17 the user need only to adjust and tighten the waist strap FIG. 17, member 32, to their desired tightness and comfort. The neck harness also has a padded cushion FIG. 17, member 63 to ensure comfort the neck area of the user.

Generally speaking, the Advanced Backpack FIG. 18 is uniquely designed whereas both shoulder straps FIG. 18, member 7 are detachable from the base via a detachable clip FIG. 18, member 9 so as the shoulder straps does not interfere with the full usage of the advance backpack.

Generally speaking, the Advanced Backpack neck harness strap FIG. 20, member 39 can easily hook onto the base off the backpack FIG. 20, member 60 via the claps on the base of the backpack FIG. 20, member 16.

The Advanced Backpack's neck/shoulder strap FIG. 21, member 29 and the Backpack's waist strap FIG. 21, member 33 are housed in a zipper on the base of compartment #5 FIG. 21, member 35.

The Advanced Backpack will advance backpacks as it contains a cup holder FIG. 22, member 24. The Advanced Backpack's cup holder is not visible FIG. 18, member 24. The user first needs to push the release button FIG. 18, member 25 for the cup holder to be retracted from its housing slot FIG. 18, member 24 and once released FIG. 22, member 24 & 25 the user can have the convenience of using the cup holder FIG. 22, member 24.

The Advanced Backpack will advance backpacks as it contains not one but TWO PORTABLE USB charging stations FIG. 23 member 38 and 39 (insert), and a charging port FIG. 23 member 37 (insert). All other backpacks with built in charging stations only has one PORTABLE USB charging station where as The Advanced Backpack will house 2 charging PORTABLE USB ports FIG. 24 member 38 and 39. This will allow the user to be able to charge 2 of their electron devices simultaneously and safely as compartment #2 FIG. 24, member 1 will be waterproof in a 360 circumference. The Advanced Backpack will also house a PORTABLE USB charging port for the recharging the charging device FIG. 24 member 37 where as the user can recharge the charging port from an electrical outlet. Some of the Advanced CHILDREN Backpack will have wheels on the bottom edges of the backpack as shown by FIGS. 25, 40 and a telescopic handle built into the top of the backpack FIGS. 25, 42 for easy traveling. The Advanced Childs backpack telescopic handle will have an adjustable arm FIGS. 25, 41 for the users comfort.

The Advanced Backpack is designed to be used by children FIG. 13 and adults FIG. 26 a like to advance the usage of the backpack from just being a backpack to becoming a backpack and a work desk.

The foregoing is considered as illustrative only of the principle of the Portable Desk Backpack. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalent may be resorted to, falling within the scope of the invention and the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention. 

What I'm claiming is a Backpack/book bag that converts into a desk comprising of:
 1. A Backpack/book bag that can convert into a desk.
 2. A Backpack/book bag and/or carrying case as claimed in claim 1 or 2 wherein the Backpack/book bag can convert into a desk and is made of materials such a Nylon, Polyester, Flux leather, Leather, Neoprene, Genuine leather and any other materials Backpack/book bag can be made from.
 3. A Backpack/book bag as claimed in claim 1 or 2 wherein a Backpack/book bag that has a leg and/or legs on the bottom of the Backpack/book bag.
 4. A Backpack/book bag as claimed in claim 1 or 2 or 3 wherein a Backpack/book bag having a leg and/or legs on that bottom of the Backpack/book bag that's Telescopic and/or foldable made of wood, plastic, fiberglass and or metal or any other material used to make telescopic and or foldable leg/legs.
 5. A Backpack/book bag as claimed in claim 1 or 2 or 3 or 4 wherein a Backpack/book bag having a single telescopic leg in middle of the bottom of the bag which is use to convert the Backpack/book bag into a desk when the telescopic leg is lowered.
 6. A Backpack/book bag as claimed in claim 1 or 2 or 3 or 4 or 5 wherein the Backpack/book bag has multiple telescopic legs more specifically 4 telescopic legs, one each corner of the bottom of the Backpack/book bag which is use to convert the Backpack/book bag into a desk when the telescopic legs are lowered.
 7. A Backpack/book bag as claimed in claim 1 or 2 or 3 or 4 or 5 wherein the Backpack/book bag legs are retractable (telescopic) which convert the Backpack/book bag into a work desk. The retractable legs can be lowered and then retracted back into its housing unit.
 8. A Backpack/book bag as claimed in claim 1 or 2 or 3 or 4 or 5 or 6 wherein the Backpack/book bag legs are adjustable with a locking mechanism that locks the Adjustable(telescopic) legs to the user's desired height.
 9. A Backpack/book bag and/or carrying case as claimed in claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 wherein the Backpack/book bag has a 360 zipper whereas the backpack/book bag can be completely detached from its base and once detached the base of the backpack/book bag can be used as a desk to write on, read on and do job functions of that of a normal desk.
 10. A Backpack/book bag as claimed in claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 wherein the Backpack/book bag base has a hard desk top surface for writing on.
 11. A Backpack/book bag claimed in claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10, wherein the Backpack/book bag that has an extendable and retractable desk top whereas when extended out the desk top becomes larger which makes for a larger desk top for the user this desk top can also be retracted back into the smaller desk top.
 12. A Backpack/book bag and/or carrying case as claimed in claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10, wherein the Backpack/book bag has a pencil holder on its desk top.
 13. A Backpack/book bag and/or carrying case as claimed in claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10, or 11 wherein the Backpack/book bag has a detachable arm and shoulder strap as to not interfere with the backpack/book bag when used as an desk.
 14. A Backpack/book bag and/or carrying case as claimed in claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 wherein the Backpack/book bag can convert into a desk and has a cup hold for beverages, an anti thief unit, a phone holder for cell phones, two USB port for charging cell phones and other devices and a charging port to charge the charging unit itself.
 15. A Backpack/book bag and/or carrying case as claimed in claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10, 11 or 12 or 13 or 14 wherein the Backpack/book bag with an adjustable handle on the top part of the backpack/book bag and wheels on the bottom of the backpack/book bag for easy traveling.
 16. A Backpack/book bag and/or carrying case as claimed in claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 wherein the Backpack/book bag with a Neck harness strap, a waist harness strap whereas the Backpack/book bag can be used as a desk in a standing position.
 17. A Backpack/book bag and/or carrying case as claimed in claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 wherein the Backpack/book bag can convert into a desk via Foldable legs. A Backpack/book bag with foldable leg hinges which allows the legs to fold down. The legs fold down and then can be adjusted to desired height.
 18. A Backpack/book bag as claimed in claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10, or 11 or 12 or 13 or 14 or 15 wherein the Backpack/book bag with 4 adjustable and retractable legs that folds down from the bottom of the Backpack IE legs on a small folding table whereas a Backpack/backpack with a latch that allows the legs on the backpack to folds down from the bottom of the Backpack's base. Which also has a locking mechanism that securely locks the adjustable legs into the base of the backpack. 